referring most likely to a 4x5, but was wondering what is the widest that would normally work with a 3x4 speed?
There is a Schneider 80mm f2.9 I've been looking at.. and wondered if it would function well on a 3x4, with enough room to use the movements if needed.
The reason for this question is that when I use the 120 roll film adapter on the 3x4, the 135 Optar gives me a to 'full' of a negative at times.

Its wrong for 4x5s too, the 4x5 Pacemaker Speed's minimum is also 66.7 mm. And its horribly wrong for 2x3s. The shortest lens I use on my 2x3 Pacemaker Speed is a 1.75"/2.8 Elcan in barrel; it covers only 6x6, though, doesn't come close to covering 2x3.

If you check data from lens makers' sites or the slightly out-of-date list of lenses on this site you'll see that there are many lenses with focal lengths as short as 60 mm +/- that will focus to infinity on your 3x4 Speed. Pay attention to coverage, I believe you need a lens that covers at least 127 mm to get good image quality in the corners.

thanks allot for the clarity... reading different posts, it seems most 3x4 speeds had a 127mm, although press people liked them for the 4x5 because of the wider image, even if they didn't get the corners.

The lens I'm looking at is not an Optar... and reading the info again, it states that it has a built-in focusing mount and depth-of-field scale, and can be used with any bellows camera set at infinity.
So no movement using it on the speed.

Yet with a roll film adapter that shoots 6x6, I really don't have to worry about the corners.

You are confusing focal length with image circle. True, a 127mm focal length is considered "normal" for the 3x4 camera but a lens needs to produce an image circle of [ the square root of 3 1/4² + 4 1/4²; 10.5625 + 18.0625=28.625 taking the square root = 5.3502336397581741495630759274711, convert to millimeters =]135.89593444985762339890212855777mm to cover the negative.
Now the actual image size is less than the negative size and the film holder specifications state that the image area is 4.228 x 3.131 so 4.228² =17.875984, 3.131² =9.803161; adding them =27.679145 and taking the square root = 5.2610973190010465724479405799684, convert to millimeters = 133.6318719026265829401776907312 to cover the image area of a 3 1/4 x 4 1/4 film holder.

Image circle needed for a roll film holder
A= the short side of the format you wish to cover
B= the long side of the format you wish to cover
C= the diagonal of the format
A²+B²=C²
1 inch = 25.4 millimeters._________________The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.

With windows calculator in Scientific mode the copy-paste makes rounding extra key strokes. _________________The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.

He told me that people like me who wanted SLRs with on-board light meters would never learn the basics. I thought he was wrong but you just proved him right.

ok.. thanks 45pps,
(for 4x5 positive post, squared)
yes I am confusing focal length with image circle... again and again..
maybe if I became a lens...
I'll have to sit down and copy ur math.. and perhaps the light will shine through to the corners.

Banjo... more clarification,, thanks.. I can use all the help I can get.

My Graphic 22 RFH has a 57mm x 57mm film opening. It requires a 81mm image circle to cover it.

My Graphic 23 RFH has a 57mm x 78mm film opening. It requires a 96.6mm image circle to cover it._________________The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.

Last edited by 45PSS on Wed May 30, 2012 7:04 pm; edited 1 time in total